LEGUMINOS^E 537 



opening until the trees flower the following year, straight, compressed, slightly toru- 

 lose, short-stalked, contracted at the apex into a short slender point, 4'-6' long and 

 I' wide, its valves somewhat membranaceous, thick-margined, reddish brown on the 



outer, yellow tinged with red on the inner surface, reticulate-veined; seeds sus- 

 pended by slender coiled and somewhat dilated f unicles, compressed, ovate to nearly 

 orbicular, dark chestnut-brown, very lustrous, \' long, and faintly marked by large 

 oval depressions; seed-coat thin, cartilaginous. 



A tree, 25-30 high, with a trunk rarely 5'-6' in diameter, slender upright 

 branches forming a narrow irregular head, and branchlets slightly striately angled, 

 covered with minute white lenticels, light gray and puberulous when they first ap- 

 pear, becoming dark brown in their second year, and armed with stout rigid stipular 

 spines sometimes ^' long and persistent for many years; more often a shrub, some- 

 times only 2-3 tall. Bark of the trunk smooth, light gray somewhat tinged with 

 red, and often marked by large pale blotches. "Wood dark-colored, hard, and heavy. 



Distribution. Bluffs and bottom-lands of the lower Rio Grande, Texas; usually 

 a low shrub spreading into broad clumps, but occasionally in the rich and compara- 

 tively moist soil of the river lagoons a slender tree; in Mexico more abundant; of 

 its largest size from the mouth of the Rio Grande to the Sierra Madre of Nuevo 

 Leon. 



3. Zygia flexicaulis, Sudw. Ebony. 



Leaves persistent, l^'-2' long, 2^'-3' wide, long-petiolate, with slender puber- 

 ulous petioles glandular near the middle and furnished at the apex with small orbic- 

 ular solitary glands, and 4-6 usually 6-foliolate pinnae, the lowest pair often the 

 shortest, persistent; leaflets ovate-oblong, rounded at the apex, reticulate-veined, 

 membranaceous or subcoriaceous, glabrous, dark green and lustrous on the upper 

 surface, paler on the lower, \'-\' long, petiolules short and broad. Flowers light 

 yellow or cream color, very fragrant, sessile in the axils of minute caducous bracts, 

 appearing from June until August, in cylindrical dense or interrupted spikes 1^' long, 

 on stout pubescent peduncles fascicled in the axils of the upper leaves of the previous 

 year; corolla four or five times as long as the calyx and like it puberulous on the outer 

 surface, and about as long as the tube formed by the union of the filaments; stamens 



